Transition-metal saccharide chemistry and biology: saccharide complexes of Cu(II) and their effect on in vivo metallothionein synthesis in mice

Abstract

Monosaccharide (D-Glc, D-Fru, D-Gal, D-Xyl, D-Rib) and disaccharide (Mal) complexes of Cu(II) were synthesized from two different precursors, viz. [NEt₄]₂ [CuCl₂Br₂] and CuCl₂.2H₂O, in nonaqueous media, and isolated in the solid state. The complexes were found to be primarily dimeric and trimeric and water soluble. These were characterized by diffuse reflectance, aqueous solution absorption, CD, FTIR, magnetic susceptibility, EPR, EXAFS, XANES, and elemental analysis. Aqueous solution stability in the pH range 4-8 was studied by cyclic voltammetry and absorption spectroscopy. The effect of subcutaneously injected Cu-Fru, Cu-Xyl, and Cu-Rib complexes on the in vivo metallothionein synthesis in mice was found to be significant in liver, but not in brain, in accordance with the observed copper accumulation in these tissues.